Printed circuit board assembly and assembling method thereof

ABSTRACT

A printed circuit board assembly includes a printed circuit board, at least one electronic device, a holder and a heat-dissipation device. The printed circuit board includes at least one first through hole. The electronic device includes a first surface, a second surface and at least one pin. The first surface and the second surface are opposite to each other, and the pin passes through the first through hole of the printed circuit board and is inserted on the printed circuit board. The holder is disposed between the printed circuit board and the electronic device. The holder includes a supporting surface sustaining the first surface of the electronic device. The heat-dissipation device includes a heat-dissipation surface attached to the second surface of the electronic device.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to China Patent Application No.201710407516.1, filed on Jun. 2, 2017. The entire contents of theabove-mentioned applications are incorporated herein by reference forall purposes.

FIELD OF THE INVENTION

The present invention relates to an assembly, and more particularly to aprinted circuit board assembly and an assembling method thereof.

BACKGROUND OF THE INVENTION

With the increasing demand for the electronic products with the highpower density, many electronic devices generate large amounts of heatduring their operation. Therefore, an effective cooling system must bearranged therewith to dissipate the heat so that the overall performanceis not affected by the heat accumulated therein. On the other hand, inorder to meet the requirements of the high power density and theheat-dissipation, such electronic device is usually disposed on theprinted circuit board by plugging pins thereon and also bending the pinsto make the electronic device attached to the heat-dissipation surfaceof the heat-dissipation device. Thus the heat generated by theelectronic device can be dissipated effectively by the heat-dissipationdevice.

Traditionally, the plug-in electronic device is fastened through theresilient fastening sheet and the screw, so that the electronic deviceis closely attached to the heat-dissipation surface of theheat-dissipation device. However, since the plug-in electronic devicehas been soldered on the printed circuit board, if the electronic deviceis further fastened through the resilient fastening sheet and the screw,it is easy to generate a tensile stress at the solder joints between thepins of the electronic device and the printed circuit board or damagethe structural body of the electronic device, and thus affect thestability of the product. In addition, in order to perform the fasteningprocess of the resilient fastening sheet and the screw, the installationlocation of the plug-in electronic device on the printed circuit boardis further limited. For example, if the electronic device ishorizontally plugged on the printed circuit board, it will occupy thelayout area of the printed circuit board for other components, whichresults in the drawbacks of reducing the available utilization area ofthe printed circuit board, increasing the size of the product anddecreasing the competitiveness of the product. Besides, while theelectronic device is vertically plugged on the printed circuit board, itis essential to provide the resilient fastening sheet and the screw withsufficient operating space for performing the fastening process toassemble the electronic device and the heat-dissipation device together.Otherwise they cannot be assembled and produced. Thus, the space betweenthe printed circuit board and the heat-dissipation device cannot beutilized easily, which also results in that the structural density ofthe system is reduced and the competitiveness of the product isdecreased.

Therefore, there is a need of providing a printed circuit board assemblyand an assembling method thereof to overcome the above drawbacks.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a printed circuit boardassembly and an assembling method thereof. By disposing a holder betweenthe printed circuit board and the heat-dissipation device, theelectronic device of the printed circuit board is correspondinglyattached to the heat-dissipation surface of the heat-dissipation deviceto dissipate heat. It is easy to assemble the electronic device, theholder, the printed circuit board and the heat-dissipation device, andthe holder is provided with sufficient strength to support theelectronic device to be heat-dissipated after the assembling structurehas been completely assembled. Consequently, the stress generated fromthe pins of the electronic device is eliminated and the electronicdevice is maintained at a fixed position. In addition, the printedcircuit board can provide sufficient available area for other electroniccomponents to be arranged unrestrictedly, so that the assemblingstructure of the printed circuit board and the heat-dissipation deviceis provided to achieve the purposes of effective heat-dissipation andhigh-density structure.

Another object of the present invention is to provide a printed circuitboard assembly and an assembling method thereof. By disposing a holderbetween the printed circuit board and the heat-dissipation device, theelectronic device is sustained by the holder firstly. Thus, while thepins of the electronic device are inserted on the printed circuit boardand the electronic device is attached to the heat-dissipation surface ofthe heat-dissipation device for dissipating heat thereof, the stressgenerated from the pins of the electronic device is eliminated and theelectronic device is maintained at a fixed position. In the meantime,the space between the printed circuit board and the heat-dissipationdevice is integrated by the support for improving the space utilization.Consequently, the assembling structure of the printed circuit board andthe heat-dissipation device is provided to achieve the purposes ofeffective heat-dissipation and high-density structure.

In accordance with an aspect of the present invention, a printed circuitboard assembly is provided. The printed circuit board assembly includesa printed circuit board, at least one electronic device, a holder and aheat-dissipation device. The printed circuit board includes at least onefirst through hole. The electronic device includes a first surface, asecond surface and at least one pin. The first surface and the secondsurface are opposite to each other, and the pin passes through the firstthrough hole of the printed circuit board and is inserted on the printedcircuit board. The holder is disposed between the printed circuit boardand the electronic device. The holder includes a supporting surfacesustaining the first surface of the electronic device. Theheat-dissipation device includes a heat-dissipation surface attached tothe second surface of the electronic device.

In accordance with another aspect of the present invention, anassembling method for a printed circuit board is provided. Theassembling method for the printed circuit board includes steps of: (a)providing a printed circuit board, at least one electronic device, aholder and a heat-dissipation device, wherein the printed circuit boardincludes at least one first through hole, the electronic device includesa first surface, a second surface and at least one pin, wherein thefirst surface and the second surface are opposite to each other, theholder includes a supporting surface, and the heat-dissipation deviceincludes a heat-dissipation surface; (b) placing the holder on theprinted circuit board, attaching the first surface of the electronicdevice to the supporting surface of the holder, and inserting the pin ofthe electronic device through the first through hole, so that the holderis disposed between the printed circuit board and the first surface ofthe electronic device and sustains the first surface of the electronicdevice; (c) fixing the pin of the electronic device on the printedcircuit board; and (d) fastening the printed circuit board on theheat-dissipation device, wherein the second surface of the electronicdevice is attached to the heat-dissipation surface.

The above contents of the present invention will become more readilyapparent to those ordinarily skilled in the art after reviewing thefollowing detailed description and accompanying drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded view illustrating a printed circuit board assemblyaccording to a first preferred embodiment of the present invention;

FIG. 2 is a perspective structural view illustrating the printed circuitboard assembly according to the first preferred embodiment of thepresent invention;

FIG. 3 is a cross-sectional view taken along line A-A of FIG. 2 andillustrating the printed circuit board assembly thereof;

FIG. 4A is a perspective structural view illustrating the holder of theprinted circuit board assembly according to the first preferredembodiment of the present invention;

FIG. 4B is another exemplary structural view illustrating the holder ofthe printed circuit board assembly according to the first preferredembodiment of the present invention;

FIG. 5 is an exploded view illustrating a printed circuit board assemblyaccording to a second preferred embodiment of the present invention;

FIG. 6 is a perspective structural view illustrating the printed circuitboard assembly according to the second preferred embodiment of thepresent invention;

FIG. 7 is a cross-sectional view taken along line B-B of FIG. 6 andillustrating the printed circuit board assembly thereof;

FIG. 8A is a perspective structural view illustrating the holder of theprinted circuit board assembly according to the second preferredembodiment of the present invention;

FIG. 8B is another exemplary structural view illustrating the holder ofthe printed circuit board assembly according to the second preferredembodiment of the present invention;

FIG. 9 is an exploded view illustrating a printed circuit board assemblyaccording to a third preferred embodiment of the present invention;

FIG. 10 is a perspective structural view illustrating the printedcircuit board assembly according to the third preferred embodiment ofthe present invention;

FIG. 11 is a perspective structural view illustrating the holder of theprinted circuit board assembly according to the third preferredembodiment of the present invention; and

FIG. 12 is a flow chart of an assembling method of a printed circuitboard assembly according to a preferred embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention will now be described more specifically withreference to the following embodiments. It is to be noted that thefollowing descriptions of preferred embodiments of this invention arepresented herein for purpose of illustration and description only. It isnot intended to be exhaustive or to be limited to the precise formdisclosed.

FIG. 1 is an exploded view illustrating a printed circuit board assemblyaccording to a first preferred embodiment of the present invention, FIG.2 is a perspective structural view illustrating the printed circuitboard assembly according to the first preferred embodiment of thepresent invention, and FIG. 3 is a cross-sectional view taken along lineA-A of FIG. 2 and illustrating the printed circuit board assemblythereof. As shown in FIGS. 1 to 3, the printed circuit board assembly(hereafter referred as the assembly) 1 includes a printed circuit board10, at least one electronic device 20, a holder 30 and aheat-dissipation device 40. The electronic device 20 includes a firstsurface 21, a second surface 22 and at least one pin 23. The firstsurface 21 and the second surface 22 are opposite to each other. Theprinted circuit board 10 includes at least one first through hole 11, atleast one second through hole 12, a third surface 13 and a fourthsurface 14. The third surface 13 and the fourth surface are opposite toeach other. In the embodiment, the pins 23 of the electronic device 20pass through the first through holes 11 of the printed circuit board 10in the direction from the third surface 13 to the fourth surface 14 andare inserted on the printed circuit board 10. The holder 30 is disposedbetween the first surface 21 of the electronic device 20 and the thirdsurface 13 of the printed circuit board 10. In the embodiment, theholder 30 includes a supporting surface 31 sustaining the first surface21 of the electronic device 20 so that the holder 30 provides asufficient strength to sustain the electronic device 20. Furthermore,the heat-dissipation device 40 includes a heat-dissipation surface 41attached to the second surface 22 of the electronic device 20.Certainly, the heat-dissipation surface 41 of the heat-dissipationdevice 40 and the second surface 22 of the electronic device 20 arefurther adhered with each other by an interface material, for examplebut not limited to a thermally conductive adhesive 50. However, thepresent invention is not limited thereto and other applicable techniquesare not redundantly described herein. In the embodiment, the electronicdevice 20 is a plug-in electronic device needing to be heat-dissipated.The electronic device 20 is firstly sustained by the holder 30 disposedbetween the printed circuit board 10 and the heat-dissipation device 40.The pins 23 of the electronic device 20 pass through the first throughholes 11 of the printed circuit board 10 and are pre-inserted on theprinted circuit board 10. Then, the pins 23 of the electronic device 20are fixed on the printed circuit board 10 by for example but not limitedto soldering. Consequently, the electronic device 20 is maintained on afixed position to prevent the pins 23 of the electronic device 20 fromgenerating the stress and being damaged while the electronic device 20is attached to the heat-dissipation surface 41 of the heat-dissipationdevice 40 directly or by the thermally conductive adhesive 50. Thus, thepurposes of the high density package and the effective heat-dissipationare achieved.

FIGS. 4A and 4B are different perspective structural views illustratingthe holder of the printed circuit board assembly according to the firstpreferred embodiment of the present invention, respectively. As shown inFIGS. 1, 2, 3, 4A and 4B, in the embodiment, the holder 30 furtherincludes an accommodation space 32 constructed between the supportingsurface 31 and the printed circuit board 10. The accommodation space 32provides a sufficient space between the printed circuit board 10 and thesupporting surface 31 for constructing other electronic components (notshown) by for example but not limited to the surface mount technology(SMT) on the third surface 13 while the holder 30 sustains theelectronic device 20. Thus, the purpose of the high density package isachieved. On the other hand, the holder 30 includes a fastening set 33jointing the holder 30 with the printed circuit board 10 together. Inthe embodiment, the fastening set 33 further includes at least onefastening hole 33 a disposed on the holder 30 and at least one fasteningpiece 33 b, and the printed circuit board 10 includes at least onesecond through hole 12. The fastening pieces 33 b are engaged with thecorresponding fastening holes 33 a through the corresponding secondthrough holes 12 in the direction from the fourth surface 14 to thethird surface 13 and joint the holder 30 with the printed circuit board10 together, so as to fasten the holder 30 on the printed circuit board10. Besides, in the embodiment, the electronic device 20 furtherincludes at least one first positioning portion 24 disposed on the firstsurface 21 and the holder 30 further includes at least one secondpositioning portion 34 disposed on the supporting surface 31. While thesupporting surface 31 of the holder 30 sustains the first surface 21 ofthe electronic device 20, the first positioning portion 24 and thesecond positioning portion 34 are engaged with each other. Consequently,it provides the position for assembling and enhances the stability ofthe holder 30 for sustaining the electronic device 20 while the firstsurface 21 of the electronic device 20 is attached to the supportingsurface 31 of the holder 30. In the embodiment, the first positioningportion 24 is a recess or a through hole, and the second positioningportion 34 is a projection. The first positioning portion 24 and thesecond positioning portion 34 fit to each other. Certainly, in anotherembodiment, the first positioning portion 24 and the second positioningportion 34 are a projection and a recess respectively and fit to eachother. They are not essential technical features to limit the presentinvention, and other applicable techniques are not redundantly describedherein.

On the other hand, in the embodiment, the printed circuit board 10 isfurther fastened on the heat-dissipation device 40. The printed circuitboard 10 includes at least one first fastening component 15 and theheat-dissipation device 40 includes at least one second fasteningcomponent 47. The first fastening component 15 and the second fasteningcomponent 47 are corresponding to each other and configured to fastenthe printed circuit board 10 on the heat-dissipation device 40. Forexample, the first fastening component 15 and the second fasteningcomponent 47 are a through hole and a screw hole, respectively, andfasten the printed circuit board 10 on the heat-dissipation device 40 bya screw (not shown). Certainly, the foregoing embodiments are merelyillustrative and not the essential technical features to limit thepresent invention. The first fastening component 15 and the secondfastening component 47 can fasten the printed circuit board 10 on theheat-dissipation device 40 by a hook, a latch, a buckle, an adhesiveglue, or other fastening means. The present is not limited thereto andother applicable techniques are not redundantly described herein. Inaddition, in the embodiment, the heat-dissipation device 40 furtherincludes a liquid-cooled heat-exchange module 42 thermally coupled tothe heat-dissipation surface 41 for effectively dissipating the heatgenerated by the electronic device 20 through the second surface 22thereof. However, they are not essential technical features to limit thepresent invention and other applicable techniques are not redundantlydescribed herein.

FIG. 5 is an exploded view illustrating a printed circuit board assemblyaccording to a second preferred embodiment of the present invention,FIG. 6 is a perspective structural view illustrating the printed circuitboard assembly according to the second preferred embodiment of thepresent invention, FIG. 7 is a cross-sectional view taken along line B-Bof FIG. 6 and illustrating the printed circuit board assembly thereof,and FIGS. 8A and 8B are different perspective structural viewsillustrating the holder of the printed circuit board assembly accordingto the second preferred embodiment of the present invention,respectively. In the embodiment, the structures, elements and functionsof the assembly 1 a are similar to those of the assembly 1 in FIGS. 1 to3, and are not redundantly described herein. Different from the assembly1 of FIGS. 1 to 3, the holder 30 a further includes at least one opening35 disposed on the supporting surface 31 and receiving the at least onepin 23 of the electronic device 20 to enable the pin 23 to pass throughthe opening 35 and be inserted on the printed circuit board 10. It isnoted that the number of the pins 23 with respect to each opening 35 isadjustable according to the practical requirements, and the opening 35is further corresponding to the plural first through holes 11 of theprinted circuit board 10, so as to provide the function of positioning.Certainly, the present invention is not limited thereto and otherapplicable techniques are not redundantly described herein. In theembodiment, the electronic device 20 to be heat-dissipated is sustainedby the holder 30 a disposed between the printed circuit board 10 and theheat-dissipation device 40, and meanwhile, the pins 23 of the electronicdevice 20 are bent and pass through the openings 35 of the holder 30 aand the first through holes 11 of the printed circuit board 10 topre-dispose the electronic device 20 on the printed circuit board 10.Then, the pins 23 of the electronic device 20 are fixed on the printedcircuit board 10 by for example but not limited to a soldering method.Consequently, the electronic device 20 is maintained at a fixed positionto prevent the pins 23 of the electronic device 20 from generating thestress and being damaged while the electronic device 20 is attached tothe heat-dissipation surface 41 of the heat-dissipation device 40directly or by the thermally conductive adhesive 50. Thus, the purposesof the high density package and the effective heat-dissipation areachieved.

On the other hand, the holder 30 a further includes at least one thirdpositioning portion 36 disposed near the outer edge of the supportingsurface 31. The heat-dissipation device 40 further includes at least onefourth positioning portion 45 corresponding to the third positioningportion 36 and disposed near the outer edge of the receiving recess 44of the heat-dissipation device 40. While the holder 30 a sustains thefirst surface 21 of the electronic device 20 and the second surface 22of the electronic device 20 is attached to the heat-dissipation surface41, the third positioning portion 36 and the fourth positioning portion45 are engaged with each other. It facilitates to assemble and positionthe holder 30 a with the heat dissipation device 40 and enhance thestability of the assembled structure of the holder 30 a and theheat-dissipation device 40. In the embodiment, the third positioningportion 36 and the fourth positioning portion 45 are a projection and arecess, respectively, and fit to each other. Certainly, in anotherembodiment, the third positioning portion 36 and the fourth positioningportion 45 can be a recess and a projection, respectively, and thedisposed positions of them are adjustable according to the practicalrequirements. The present invention is not limited thereto. It is notedthat, in the embodiment, the third positioning portion 36 and thefastening hole 33 a of the holder 30 a are integrated into one piece.The second positioning portion 34 of the holder 30 a and the firstpositioning portion 24 of the electronic device 20 are engaged with eachother and the third positioning portion 36 of the holder 30 a and thefourth positioning portion 45 of the heat-dissipation device 40 areengaged with each other. Further, the fastening piece 33 b passesthrough the second through hole 12 of the printed circuit board 10 andis engaged with the fastening hole 33 a integrated with the thirdpositioning portion 36 as one piece to connect the holder 30 a and theprinted circuit board 10. Thus, the printed circuit board 10, the holder30 a, the electronic device 20 and the heat-dissipation device 40 areassembled and positioned easily and firmly.

In addition, in the embodiment, the holder 30 a further includes a fifthpositioning portion 37 corresponding to the first fastening component 15of the printed circuit board 10 and the second fastening component 47 ofthe heat-dissipation device 40 and disposed on the holder 30 a. Theheat-dissipation device 40 further includes a sixth positioning portion46 corresponding to the fifth positioning portion 37 of the holder 30 a.In the embodiment, the first fastening component 15 and the secondfastening component 47 are a through hole and a screw hole,respectively. The sixth positioning portion 46 and the second fasteningcomponent 47 of the heat-dissipation device 40 are integrated as aone-piece cylinder. By a screw (not shown) passing through the throughhole of the first fastening component 15 and the through hole of thefifth positioning portion 37 and engaged with the screw hole of thesecond fastening component 47 on the cylinder of the sixth positioningportion 46, the printed circuit board 10, the holder 30 a and theheat-dissipation device 40 are positioned and assembled easily andfirmly. On the other hand, different from the assembly 1 of FIGS. 1 to3, in the embodiment, the heat-dissipation device 40 further includes aheat sink 43 thermally coupled to the heat-dissipation surface 41 andconfigured to effectively dissipate the heat generated by the electronicdevice 20 through the second surface 22. It is not an essentialtechnical feature to limit the present invention and other applicabletechniques are not redundantly described herein.

FIG. 9 is an exploded view illustrating a printed circuit board assemblyaccording to a third preferred embodiment of the present inventionwherein the printed circuit board is omitted, FIG. 10 is a perspectivestructural view illustrating the printed circuit board assemblyaccording to the third preferred embodiment of the present inventionwherein the printed circuit board is omitted, and FIG. 11 is aperspective structural view illustrating the holder of the printedcircuit board assembly according to the third preferred embodiment ofthe present invention. In the embodiment, the structures, elements andfunctions of the assembly 1 b are similar to those of the assembly 1 aof FIGS. 5 to 7, and are not redundantly described herein. In theembodiment, the assembly 1 b includes a printed circuit board 10(referring to FIG. 5), at least one electronic device 20, a holder 30 band a heat-dissipation device 40. Different from the assembly 1 a ofFIGS. 5 to 7, in the embodiment, the holder 30 b further includes apushing piece 31 b configured to construct the supporting surface 31 a.The pushing piece 31 b can be for example but not limited to a resilientsheet, a spring, an adjustment screw and so on. The electronic device 20includes two lateral sides 25 connected between the first surface 21 andthe second surface 22, and the at least one pin 23 is disposed betweenthe two lateral sides 25. The heat-dissipation device 40 furtherincludes at least two receiving portions 48 disposed at two oppositesides of the heat-dissipation surface 41. On the other hand, the holder30 b further includes at least two extending portions 38 extended fromthe supporting surface 31 a constructed by the pushing piece 31 b andalong the two lateral sides 25 of the electronic device 20, and bentportions 38 a located at the front end of the at least two extendingportions 38 are attached to the at least two corresponding receivingportions 48 of the heat-dissipation device 40, respectively. The pushingpiece 31 b and the at least two extending portions 38 of the holder 30 bare constructed together to form a receiving seat 39 to receive theelectronic device 20 and attach the second surface 22 of the electronicdevice 20 to the heat-dissipation surface 41 of the heat-dissipationdevice 40. In the embodiment, the electronic device 20 to beheat-dissipated is sustained by the holder 30 b. The pins 23 of theelectronic device 20 are bent and pass through the first through holes11 of the printed circuit board 10 (referring to FIGS. 5 to 7) topre-dispose the electronic device 20 on the printed circuit board 10.Then, the pins 23 of the electronic device 20 are fixed on the printedcircuit board 10 by for example but not limited to a soldering method.Consequently, the electronic device 20 is maintained at a fixed positionto prevent the pins 23 of the electronic device 20 from generating thestress and being damaged while the electronic device 20 is attached tothe heat-dissipation surface 41 of the heat-dissipation device 40. Thus,the purposes of the high density package and the effectiveheat-dissipation are achieved.

It is noted that the front-end bent portions 38 a of the at least twoextending portions 38 of the holder 30 b are correspondingly attached tothe at least two receiving portions 48. The thickness of the bentportions 38 a is substantially the same as the height difference betweenthe heat-dissipation surface 41 and the bottom surface of the receivingportions 48 of the heat-dissipation device 40. While the pushing piece31 b and the extending portions 38 of the holder 30 b are configured toreceive the electronic devices 20 with the different dimensionaltolerances, the first surface 21 of the electronic device 20 is pushedby the supporting surface 31 a constructed by the pushing piece 31 b.Consequently, the second surface 22 of the electronic device 20 isattached to the front-end bent portions 38 a of the two extendingportions 38 and the heat-dissipation surface 41. Therefore, the holder30 b provides not only the function of supporting the electronic devices20 but also the function of adjusting the dimensional tolerances of theelectronic devices 20.

According to the assemblies 1, 1 a, 1 b of the above embodiments, thepresent invention further provides the assembling method of the printedcircuit board assembly. FIG. 12 is a flow chart of an assembling methodof a printed circuit board assembly according to a preferred embodimentof the present invention. Please refer to FIGS. 1 to 3, 5 to 7, 9 to 11and 12, the assembling method of the printed circuit board assemblyincludes the following steps. Firstly, as shown in the step S1 of FIG.12, a printed circuit board 10, at least one electronic device 20, aholder 30, 30 a, 30 b and a heat-dissipation device 40 are provided. Theprinted circuit board 10 includes at least one first through hole 11.The electronic device 20 includes a first surface 21, a second surface22 and at least one pin 23. The first surface 21 and the second surface22 are opposite to each other. The holder 30, 30 a, 30 b includes asupporting surface 31, 31 a. Afterward, the holder 30, 30 a, 30 b isplaced on the printed circuit board 10, the first surface 21 of theelectronic device 20 is attached to the supporting surface 31, 31 a ofthe holder 30, 30 a, 30 b, and the pins 23 of the electronic device 20are partially inserted through the first through holes 11 of the printedcircuit board 10. Consequently, the holder 30, 30 a, 30 b is disposedbetween the printed circuit board 10 and the first surface 21 of theelectronic device 20 and sustains the first surface 21 of the electronicdevice 20, as shown in the step S2 of FIG. 12. Then, the pins 23 of theelectronic device 20 are firmly fixed on the printed circuit board 10 byfor example but not limited to a soldering method, as shown in the stepS3 of FIG. 12. Thus, the electronic device 20 is sustained by the holder30, 30 a, 30 b to be maintained at a fixed position so as to prevent thepins 23 of the electronic device 20 from generating the stress and beingdamaged.

In the embodiment, the assembling method of the printed circuit boardassembly further includes a step of fastening the printed circuit board10 on the heat-dissipation device 40, as shown in the step S4 of FIG.12. At the meantime, the second surface 22 of the electronic device 20is attached to the heat-dissipation surface 41. In the embodiment, theprinted circuit board 10 includes at least one first fastening component15 and the heat-dissipation device 40 includes at least one secondfastening component 47. The first fastening component 15 and the secondfastening component 47 are a through hole and a screw hole,respectively, and fasten the printed circuit board 10 on theheat-dissipation device 40 by a screw (not shown). Certainly, the firstfastening component 15 and the second fastening component 47 can alsofasten the printed circuit board 10 on the heat-dissipation device 40 bya hook, a latch, a buckle, an adhesive tape, or other fastening means.The present invention is not limited thereto and other applicabletechniques are not redundantly described herein. It should be emphasizedthat the electronic device 20 can be sustained effectively by the holder30, 30 a, 30 b to maintain the electronic device 20 at a fixed position.While the holder 30, 30 a, 30 b is disposed between the printed circuitboard 10 and the first surface 21 of the electronic device 20 andsustains the electronic device 20, the pins 23 of the electronic device20 are pre-inserted through the first through holes 11 of the printedcircuit board 10. Furthermore, the pins 23 of the electronic device 20can be fixed on the printed circuit board 10 by for example but notlimited to a soldering method after the printed circuit board 10 isfastened on the heat-dissipation device 40. The assembling proceduresare adjustable according to the real requirements. On the other hand,the heat-dissipation device 40 is further thermally coupled to aliquid-cooled heat-exchange module 42 or a heat sink 43 through theheat-dissipation surface 41 for effectively dissipating the heatgenerated by the electronic device 20 through the second surface 22 andavoiding the high-temperature heat accumulation to damage the electronicdevice 20.

In addition, it is noted that the electronic device 20 of the presentinvention is sustained by the holder 30, 30 a, 30 b so as to pre-insertthe pins 23 of the electronic device 20 through the first through holes11 of the printed circuit board 10. At the meantime, the firstpositioning portion 24 of the electronic device 20 is engaged with andthe second positioning portion 34 of the holder 30, 30 a so as topre-dispose the electronic device 20 on the holder 30, 30 a. Then, whilethe printed circuit board 10 and the holder 30, 30 a are assembledtogether, the pins 23 of the electronic device 20 pass through the firstthrough holes 11 of the printed circuit board 10, and the electronicdevice 20, the holder 30, 30 a and the printed circuit board 10 aremaintained at the fixed positions. Since the electronic device 20, theholder 30, 30 a and the printed circuit board 10 are maintained at thefixed positions, while the pins 23 of the electronic device 20 arefirmly soldered on the printed circuit board 10, there is no stressgenerated at the solder joints between the pins 23 and the printedcircuit board 10. Certainly, the electronic device 20 can bepre-disposed in the receiving seat 39 constructed by the pushing piece31 b and the two extending portions 38 of the holder 30 b. Then, theholder 30 b with the pre-disposed electronic device 20 is fixed on theprinted circuit board 10 by for example but not limited to a screw, ahook, a latch, a buckle, an adhesive tape, or other fastening means. Atthe meantime, the pins 23 of the electronic device 20 pass through thefirst through holes 11 and pre-inserted on the printed circuit board 10.Similarly, since the electronic device 20, the holder 30 b and theprinted circuit board 10 are maintained at the fixed positions, whilethe pins 23 of the electronic device 20 are soldered on the printedcircuit board 10, there is no stress generated at the solder jointsbetween the pins 23 and the printed circuit board 10.

It should be emphasized that, in the assembling method of the printedcircuit board assembly, the electronic device 20, the holder 30, 30 a,30 b and the printed circuit board 10 are maintained at the fixedpositions before the pins 23 of the electronic device 20 are fixed onthe printed circuit board 10 by for example but not limited to asoldering method. Then, while the pins 23 of the electronic device 20are firmly soldered on the printed circuit board 10, there is no stressgenerated. On the other hand, since the electronic device 20, the holder30, 30 a, 30 b and the printed circuit board 10 are maintained at thefixed positions, while the electronic device 20 is attached to theheat-dissipation surface 41 of the heat-dissipation device 40 directlyor by the thermally conductive adhesive 50, there is no stress generatedat the joints between the pins 23 and the printed circuit board 10 so asto avoiding the damage. In addition, while the holder 30, 30 a, 30 b isdisposed between the printed circuit board 10 and the first surface 21of the electronic device 20 and sustains the first surface 21 of theelectronic device 20, the pins 23 of the electronic device 20 areinserted through the first through holes 11 of the printed circuitboard. No matter whether the printed circuit board 10 is fixed on theheat-dissipation device 40 in advance, the pins 23 of the electronicdevice 20 can be fixed on the printed circuit board 10 by for examplebut not limited to a soldering method to avoid generating any stress atthe joints between the pins 23 and the printed circuit board 10 and thusavoid the damage. The present invention is not limited to the aboveillustrative embodiments, and the assembling sequences are adjustableaccording to the real requirements and not redundantly described herein.

In summary, the present disclosure provides a printed circuit boardassembly and an assembling method thereof. By disposing a holder betweenthe printed circuit board and the heat-dissipation device, theelectronic device on the printed circuit board is correspondinglyattached to the heat-dissipation surface of the heat-dissipation deviceto dissipate heat. It is easy to assemble the electronic device, theholder, the printed circuit board and the heat-dissipation device, andthe holder is provided with sufficient strength to support theelectronic device to be heat-dissipated after the assembling structurehas been completely assembled. Consequently, the stress generated fromthe pins of the electronic device is eliminated and the electronicdevice is maintained at a fixed position. In addition, the printedcircuit board can provide sufficient available area for other electroniccomponents to be arranged unrestrictedly, so that the assemblingstructure of the printed circuit board and the heat-dissipation deviceis provided to achieve the purposes of effective heat-dissipation andhigh-density structure. Moreover, by disposing a holder between theprinted circuit board and the heat-dissipation device, the electronicdevice is sustained by the holder firstly. Thus, while the pins of theelectronic device are inserted on the printed circuit board and theelectronic device is attached to the heat-dissipation surface of theheat-dissipation device, the stress generated from the pins of theelectronic device is eliminated and the electronic device is maintainedat a fixed position. In the meantime, the space between the printedcircuit board and the heat-dissipation device is integrated by theholder for improving the space utilization. Consequently, the assemblingstructure of the printed circuit board and the heat-dissipation deviceis provided to achieve the purposes of effective heat-dissipation andhigh-density structure.

While the invention has been described in terms of what is presentlyconsidered to be the most practical and preferred embodiments, it is tobe understood that the invention needs not be limited to the disclosedembodiment. On the contrary, it is intended to cover variousmodifications and similar arrangements included within the spirit andscope of the appended claims which are to be accorded with the broadestinterpretation so as to encompass all such modifications and similarstructures.

1. A printed circuit board assembly comprising: a printed circuit boardincluding at least one first through hole; at least one electronicdevice including a first surface, a second surface and at least one pin,wherein the first surface and the second surface are opposite to eachother, and the pin passes through the first through hole of the printedcircuit board and is inserted on the printed circuit board; a holderdisposed between the printed circuit board and the electronic device,wherein the holder includes a supporting surface sustaining the firstsurface of the electronic device; and a heat-dissipation deviceincluding a heat-dissipation surface attached to the second surface ofthe electronic device.
 2. The printed circuit board assembly accordingto claim 1, wherein the holder further comprises an accommodation spaceconstructed between the supporting surface and the printed circuitboard.
 3. The printed circuit board assembly according to claim 1,wherein the holder comprises a fastening set jointing the holder withthe printed circuit board, the fastening set comprises at least onefastening hole and at least one fastening piece, the printed circuitboard comprises at least one second through hole, and the fasteningpiece is engaged with the fastening hole on the holder through thesecond through hole and joints the holder with the printed circuitboard.
 4. The printed circuit board assembly according to claim 1,wherein the electronic device further comprises a first positioningportion disposed on the first surface, the holder further comprises asecond positioning portion disposed on the supporting surface, and whilethe supporting surface of the holder sustains the first surface of theelectronic device, the first positioning portion and the secondpositioning portion are engaged with each other.
 5. The printed circuitboard assembly according to claim 1, wherein the holder furthercomprises at least one opening disposed on the supporting surface andreceiving the at least one pin of the electronic device to passtherethrough and be inserted on the printed circuit board.
 6. Theprinted circuit board assembly according to claim 1, wherein the holderfurther comprises a pushing piece configured to construct the supportingsurface.
 7. The printed circuit board assembly according to claim 6,wherein the electronic device comprises two lateral sides connectedbetween the first surface and the second surface, the at least one pinis disposed between the two lateral sides, the heat-dissipation devicefurther comprises at least two receiving portions disposed at twoopposite sides of the heat-dissipation surface, and the holder furthercomprises at least two extending portions extended from the supportingsurface and along the two lateral sides of the electronic device toattach to the at least two corresponding receiving portions of theheat-dissipation device, respectively.
 8. The printed circuit boardassembly according to claim 7, wherein the pushing piece and the atleast two extending portions are constructed together to form areceiving seat to receive the electronic device and attach the secondsurface of the electronic device to the heat-dissipation surface of theheat-dissipation device.
 9. The printed circuit board assembly accordingto claim 1, wherein the holder further comprises a third positioningportion, the heat-dissipation device further comprises a fourthpositioning portion, and while the holder sustains the first surface ofthe electronic device and the second surface of the electronic device isattached to the heat-dissipation surface, the third positioning portionand the fourth positioning portion are engaged with each other.
 10. Theprinted circuit board assembly according to claim 1, wherein the printedcircuit board comprises at least one first fastening component and theheat-dissipation device comprises at least one second fasteningcomponent, and the first fastening component and the second fasteningcomponent are corresponding to each other and configured to fasten theprinted circuit board on the heat-dissipation device. 11-20. (canceled)21. An electronic assembly for use with a printed circuit board andconfigured to couple with a heat dissipation device, the electronicassembly comprising: at least one electronic device including a firstsurface, a second surface and at least one pin, wherein the firstsurface and the second surface are opposite to each other, and the pinis configured to pass through a first through hole of the printedcircuit board and inserted on the printed circuit board, wherein thesecond surface of the electronic device is attachable to aheat-dissipation surface of the heat-dissipation device; and a holderdisposed between the printed circuit board and the electronic device,wherein the holder includes a supporting surface sustaining the firstsurface of the electronic device.
 22. The electronic assembly accordingto claim 21, wherein the holder further comprises an accommodation spaceconstructed between the supporting surface and the printed circuitboard.
 23. The electronic assembly according to claim 21, wherein theholder comprises a fastening set jointing the holder with the printedcircuit board, the fastening set comprises at least one fastening holeand at least one fastening piece, and the fastening piece is engagedwith the fastening hole on the holder through a second through hole ofthe printed circuit board and joints the holder with the printed circuitboard.
 24. The electronic assembly according to claim 21, wherein theelectronic device further comprises a first positioning portion disposedon the first surface, the holder further comprises a second positioningportion disposed on the supporting surface, and while the supportingsurface of the holder sustains the first surface of the electronicdevice, the first positioning portion and the second positioning portionare engaged with each other.
 25. The electronic assembly according toclaim 21, wherein the holder further comprises at least one openingdisposed on the supporting surface and receiving the at least one pin ofthe electronic device to pass therethrough and be inserted on theprinted circuit board.
 26. The electronic assembly according to claim21, wherein the holder further comprises a pushing piece configured toconstruct the supporting surface.
 27. The electronic assembly accordingto claim 26, wherein the electronic device comprises two lateral sidesconnected between the first surface and the second surface, the at leastone pin is disposed between the two lateral sides, and the holderfurther comprises at least two extending portions extended from thesupporting surface and along the two lateral sides of the electronicdevice to attach to at least two corresponding receiving portionsdisposed at two opposite sides of the heat-dissipation device,respectively.
 28. The electronic assembly according to claim 27, whereinthe pushing piece and the at least two extending portions areconstructed together to form a receiving seat to receive the electronicdevice and attach the second surface of the electronic device to theheat-dissipation surface of the heat-dissipation device.
 29. Theelectronic assembly according to claim 21, wherein the holder furthercomprises a third positioning portion, and while the holder sustains thefirst surface of the electronic device and the second surface of theelectronic device is attached to the heat-dissipation surface, the thirdpositioning portion engages with a fourth positioning portion of theheat-dissipation device.
 30. The electronic assembly according to claim21, wherein the supporting surface includes an inclined plane.